Rutgers researchers are on the cusp of introducing an accurate test for Lyme disease.
When word got out in 2009 that two scientists from Rutgers’ Public Health Research Institute, at New Jersey Medical School, were working on a new and vastly improved test for Lyme disease, Lyme sufferers besieged the pair with phone calls and emails asking when it might become available. Existing tests for the disease, which is caused by the bacterium Borrelia burgdorferi and transmitted by blacklegged ticks, are notoriously imperfect. And if the disease goes untreated in its early stages, its effects—including damage to the joints, heart, and nervous system—can be devastating. In fact, the Centers for Disease Control and Prevention (CDC) estimates that 90 percent of Lyme cases go undiagnosed. Given that 30,000 cases are diagnosed in the United States annually (and that Lyme is endemic in roughly 80 other countries), an accurate test for the disease has been the holy grail of researchers and patients for decades.
In innumerable phone and email responses, the researchers—Nikhat Parveen, an associate professor in the Department of Microbiology, Biochemistry, and Molecular Genetics at the medical school, and Salvatore A.E. Marras, an assistant professor in the same department—had to explain that it could be years before the test becomes widely available. At that point, they’d only tested the assay (as such tests are known to diagnosticians) on the blood of mice; while it would likely yield similar results in human blood, no one knew that for sure. And once the initial testing process was complete, the researchers would have to find a manufacturer for the assay, which would then require approval by the Food and Drug Administration (FDA).
Today, the test is significantly closer to widespread availability. Parveen and Marras have applied for a patent and are in communication with a company interested in developing and marketing it. It could still take a year or more before the assay is licensed and receives FDA approval, but assuming it does, it will surely change lives.
What makes the test so important to those suffering—or who think they may be suffering—from Lyme disease is its potential for accuracy. Current FDA-approved assays reveal the presence of antibodies to the Lyme bacterium, but because those antibodies remain in the blood even after the Borrelia bacteria are no longer present, it’s impossible to tell from the results whether or not the infection is still active. The tests can also produce false negatives, indicating that Lyme isn’t present when, in fact, it is. The CDC recommends that current tests be used only as supporting evidence for a diagnosis made on the basis of symptoms and medical history.
Parveen and Marras’s assay would change all that. Not long after she arrived at the institute in 2005, Parveen attended a lecture in which Marras spoke about molecular beacons, a technology he’d invented along with research partners Fred Kramer and Sanjay Tyagi. The beacons are microscopic probes synthesized from genetic material, designed to fluoresce brightly when they come into contact with a target molecule of DNA or RNA. Marras compares them to “little lanterns that will go on only when their specific pathogen is present.” Parveen knew at once, she says, “that I wanted to incorporate them into my research.” Thanks to its use of molecular beacons, the new blood test is able to reveal the presence of the bacteria themselves rather than antibodies to them. What makes molecular beacons such a powerful diagnostic tool is the fact that they can be engineered to detect multiple pathogens in a single blood sample. “You can put in a green bulb, say, for Borrelia and a red bulb for something else,” Marras says.
That’s an important step forward: Parveen, whose work on tick-borne pathogens earned her a 2015 Excellence in Research award from the New Jersey Health Foundation, was well aware that the Lyme bacterium isn’t the only pathogen making its home in blacklegged ticks. Two other bad actors, the bacterium Anaplasma phagocytophilum and the parasite species Babesia, have been found in the same ticks that harbor the bacteria that cause Lyme disease, and their effects can be equally pernicious. Although the diseases they cause—anaplasmosis and babesiosis—can be asymptomatic, particularly in their early stages, their symptoms, such as fever, headache, and malaise, can also mimic those of Lyme disease. It’s conceivable, then, that a person could be infected with all three pathogens at once, which makes an assay that can detect them all particularly valuable, especially given that bacterial and parasitic diseases require different treatments.
The test’s ability to find Anaplasma and Babesia in blood samples also makes it potentially valuable to blood banks, which at present have no way to test for the pathogens. Both diseases can be spread by blood transfusions and, because they’re often asymptomatic in early stages, infectious microbes can enter the nation’s blood supply with relative ease. (Lyme tends not to be a problem in the blood supply because its symptoms, for the majority of sufferers, appear early in an infection.) In fact, the first FDA-approved use of the test might well be among blood banks, although Parveen and Marras expect that it will eventually be used to diagnose disease in patients as well. “The advantage of our assay,” says Parveen, “is that it can be used in both settings”—ensuring a safer blood supply and a healthier world. •